OS1613 Electrical properties of YSZ under in-plane compressive stress
Details
Lattice volume of solid state ionic conductors was closely related to its electrical properties, because oxygen ion, proton and other ionic carriers migrate via hopping between sights in lattice. Therefore, in the case of conventional developing of ionic conductors, i.e. doping different valent element, lattice volume change caused by doping had been discussed. In this study, we attempted the effect of outer forces to lattice volume and its influence to electrical properties. Yttrium stabilized zirconia was adopted to be objective materials, because it is most popular electrolyte material for SOFCs. Single crystalline pellets of YSZ were fitted into the basement made of Al_2O_3 and Si_3N_4 at room temperature, and annealed. Compressive outer forces was applied in axial directions because thermal expansion coefficient is differ between YSZ (10.3×10^<-6> K^<-1>), Al_2O_3 (7.7×10^<-6> K^<-1>) and Si_3N_4 (3.2×10^<-6> K^<-1>). The applied forces reached to 800 MPa at 800 oC with the Si_3N_4 basement. Electrical conductivity of YSZ pellets was measured in vertical direction to stress plane, and the influence of lattice modulation was discussed.
